God's Law is eternal. The temple rules are null because there is no temple. There are rules for the priesthood that will not apply.
but the Ten Commandments are not void. Never will be.
The Feasts and Calendar of the OT are NOT Jewish feasts and rituals, they are GOD'S Feast and GOD'S Holy Days and GOD'S calendar.
The "one who sought to change the times and seasons of the Lord" has done the damage already.
The gregorian calendar and the man-made holidays created by the church of Rome and their new brand of Christianity are NOT eternal and NOT of God.
Many of those who practiced the religion of Judaism were guilty of (and admonished severely for by Jesus) adding to the perfect Law of God with the 100's of extra rules to abide by and those things that they practiced took them from the True worship of God that Jesus was teaching. So often when the NT refers to the burdensome laws practiced it is referring to those that came from extra-biblical rabbinical writings. And unfortunately, many Christians took that to mean that God's Law was the obsolete and burdensome laws. God, nor Jesus, nor any apostle ever referred to the Ten Commandments as something we should not worry about obeying.
Ever.
The same way that new (and false) doctrine was incorporated into the practices of many Christians in the 1st thru 4th centuries due to the attempt to scrub the 'jewishness' from the religion by the catholic fathers. The religion that became catholicism is but a syncretization of greco-roman practices and the True WAY that Paul and the apostles taught. and practiced.
The church of Rome wanted so bad to convert people to their brand of religion (with demonic results) stated flatly that it was okay for newly converted believers to keep their pagan rituals and feasts as long as they pledge allegiance to Rome.
So then Martin Luther came along and recognized that the church of Rome had done what Mark 7 warned about.
He however did not do enough reform in my opinion. He was on the right track, but alas, we are left with her daughters, the protestant churches, full of customs and traditions of man taught as doctrine.
This is why I believe that Jesus wanted us all to keep the Commandments, Feasts and Sabbaths.
Because He did.
John 14:15